Projection lens, in particular for microlithography

ABSTRACT

A projection lens ( 3 ), in particular for microlithography, is provided with an object plane ( 7 ), with an image plane ( 9 ), with a lens arrangement ( 4 ) and with at least one gas chamber filled with gas or through which gas flows. The gas chamber is constructed as an approximately plane-parallel manipulation chamber ( 13 ). The refractive index can be varied in the manipulation chamber ( 13 ) by pressure changes and/or changes in gas composition

BACKGROUND OF THE INVENTION

[0001] The invention relates to a projection lens, in particular formicrolithography and having a lens arrangement, according to the typedefined in more detail in the preamble of claim 1. The invention alsorelates to a method for producing microstructured components with theaid of a projection exposure machine.

[0002] It is already known from U.S. Pat. No. 4,871,237 to tune a lensas a function of barometric pressure, specifically via the refractiveindex of a filling gas in the lens interspace. It is possible, forexample, to correct spherical aberration, coma and other faults by asuitable combination of interspaces. However, it is a disadvantage ofthis lens that other faults are initiated with the removal of one error,for example a spherical aberration.

[0003] U.S. Pat. No. 4,676,614 discloses a projection exposure machinewhich comprises a gas chamber to which pressure can be applied. Imageerrors caused by a change in atmospheric pressure can be compensated bya specific application of pressure.

[0004] U.S. Pat. No. 5,559,584 discloses introducing protective gas intothe interspace between a wafer and/or a reticle and the projection lensin the case of a projection exposure machine for producingmicrostructured components.

[0005] In the case of lithographic lenses, spherical aberration, interalia, arises as image error owing to environmental influences, such aschange in air pressure, for example. Other parameters are lens heatingand compaction, which likewise lead to spherical aberration.Particularly in the case of a high numerical aperture, the absolutevalue of the spherical aberration becomes very large and no longertolerable given the required accuracies.

[0006] In addition to U.S. Pat. 4,871,237, mentioned at the beginning,it is known to compensate barometric and weather-induced pressurechanges by wavelength changes in the case of DUV lenses. However, for365 nm, 193 nm lenses this method no longer functions and specificallythe chromatic correction of the lenses, that is to say the use ofdifferent materials, causes the different variation in the refractiveindices with the wavelength to lead to image errors which cannot betolerated.

[0007] It is also known from practice to compensate residual errors,caused by environmental influences, by using z manipulators, that is tosay lens elements which can be actively displaced in the direction ofthe optical axis. However, it is disadvantageous of this method that inaddition to the large outlay required therefore other errors are onceagain introduced thereby as well.

[0008] It is therefore common to all known methods that they more orless effectively compensate spherical aberration but at the same timeonce again introduce other errors, or act only incompletely. Acomplicating factor is added when the optical materials used, inparticular lenses, consist of different materials such as, for example,calcium fluoride and quartz glass, because this gives rise todifferently varying refractive indices over the wavelength, should it bedesired to manipulate over the wavelength.

SUMMARY OF THE INVENTION

[0009] It is the object of the present invention to create a projectionlens which has with fewer lenses a very good quality, in particular alsoin the case of a high aperture, it also being desirable to providecorrection options at the same time. It is desired, in particular, topermit correction of the constant field component of a sphericalaberration. It is likewise the object of the invention to create amethod for producing microstructured components in the case of whichspherical aberration can be corrected as far as possible.

[0010] Given parallel chambers and elements bounded by flat surfaces,only spherical aberration occurs in effective telecentric systems whenthere is a change in refractive index, in particular downstream andupstream of an end plate. This fact has now been utilized in the deviceaccording to the invention. Pressure changes in such a chamber changethe spherical aberration. The same also holds for the change in a gascomposition. This state of affairs is now utilized according to theinvention for active manipulation for spherical aberration.

[0011] If, in this case, the manipulation chamber is disposed between alast end plate upstream of the substrate to be illuminated and theoptical lens situated adjacent to the end plate, which in this case mustbe flat on the side facing the end plate, the spherical aberrationproduced “artificially” in this way can avoid or appropriately corrector compensate an aberration of the lens by changing the pressure in themanipulation chamber and/or the gas composition and/or the activecontrol thereof.

[0012] The same also holds when the manipulation chamber is installedbetween the template and the image plane.

[0013] It is advantageous to set an offset of the refractive index inadvance via a specific initial gas mixture, in order to permit changesin refractive index in both directions, that is to say raising andlowering it.

[0014] In other words, if the refractive index is changed in themanipulation chamber, spherical aberration (constant fieldcharacteristic) is introduced virtually exclusively. The change in therefractive index is achieved according to the invention by the selectedcomposition of the gas or gas mixture to be introduced into themanipulation space, and/or of the pressure.

[0015] In order not to introduce any new errors by additional pressure,for example by sagging of the surfaces delimiting the manipulationchamber, the elements closing off the manipulation chamber mustcorrespond to the specified diameter/thickness ratios.

[0016] In a very advantageous development of the invention, it can beprovided that a further manipulable gas interspace is provided inaddition to the manipulation chamber. The further gas interspace can beprovided with a low refractive power, that is to say at least onesurface delimiting the gas interspace in the z direction is providedwith a slight curvature. If a gas or a gas mixture is likewiseintroduced into this gas interspace, the refractive power can be variedby changing the gas mixture or else by a pressure change. It is possiblein this way to change any field curvature arising on the substrate to beexposed. Specifically, imaging as accurately as possible on the flatsubstrate requires the absence of any field curvature. If, for example,the field curvature changes owing to lens warming, this disadvantageousfield curvature can now be removed according to the invention by thefurther manipulable gas interspace. This holds, in particular, wheneverthe latter is situated as close as possible to the substrates to beexposed. At the same time, it is thereby avoided that other errors areproduced again thereby.

[0017] The construction according to the invention of an optical elementaccording to claim 8, which more or less has a shape which is at leastapproximately plane parallel, and the specified thickness, which isgreater by comparison with known optical elements such as, for example,an end plate of a lens yield the advantage that, for example, owing tothe plane parallelism of the optical element there is only aninsubstantial variation in image errors arising from the thick elementover the field. This element always reacts identically over the imagefield, because the lens is telecentric in this region. Since thisoptical element has no radii of curvature or at least none worthmentioning, no radii can exert an unfavorable influence in any way atall, in particular when the field increases or the aperture increases,for example. In other words: the optical element having the dimensionsaccording to the invention no longer leads to any variations, and thismeans that specific aberrations in the widely opened lens can be betterpredicted in principle and can in this way be corrected further at thefront or as early as in the input region.

[0018] When, in a very advantageous embodiment of the invention, it isprovided that the optical element and a further optical element of thesixth optical group enclose a gas chamber, in which case it holds forthe radius of curvature R3 of the surface of the second optical element,which faces the first lens, that: R3>3000 mm, preferably >5000 mm, thisproduces a quasi plane-parallel gas chamber which can be used asmanipulation chamber in a very advantageous way for the invention.

[0019] A further, very advantageous and not obvious development of theinvention in the use of an optical element in the sixth lens group withthe specified radii of curvature and diameter/thickness ratios consistsin that a lens with an aspheric is provided in the first lens cluster.

[0020] Corrections, such as the removal of shell errors and fieldcurvature, for example, can be achieved with the aid of the asphericaccording to the invention as early as in the input region of the lens.This holds, in particular, in the case of very widely opened lenses, inparticular when the aspheric is fitted as near as possible to the inputof the lens, at least in front of the first bulge, at best already onthe first curved surface.

[0021] It is thereby possible according to the invention to achieveapertures of at least 0.75, preferably 0.85, it being possible,nevertheless, still to fit a very thick optical element on the outputside, for example a thick end plate. Since an optical element inaccordance with claim 1 no longer experiences variations, it ispossible, for example, to predict the aberration, that is to say how itdevelops in the lens. The aspheric according to the invention can beused to influence and/or correct the aberration correspondingly. Thiscan be done here in an advantageous way in a region in which theaperture is still relatively small.

[0022] The bundle of light can be even more effectively separated whenthe aspheric is arranged in front of the first light bulge.

[0023] According to the invention, the sixth optical group can consistonly of plane-parallel plates. Of course, it is also possible to provideone or two lenses in the sixth optical group, in which case at least onelens should then have an at least approximately flat surface which issituated adjacent to a further plane-parallel surface, for example anend plate, so that the manipulation chamber according to the inventioncan then be formed therebetween.

[0024] It is also advantageous when lenses in the sixth lens clusterand, if appropriate, also in the fifth lens cluster, that is to saylenses which are situated nearest a wafer in microlithography, have onlya positive refractive power. At least two or three appropriate lenseswill preferably be arranged at this point.

[0025] Advantageous developments of the invention follow from theremaining subclaims and from the exemplary embodiments described belowin principle with the aid of the drawing.

[0026] It is true that only purely refractive lenses are shown in theexemplary embodiments illustrated, but this invention is not limited torefractive systems, but can also read on catadioptric systems.

CONCISE DESCRIPTION OF THE DRAWINGS

[0027] In the drawing:

[0028]FIG. 1 shows a diagrammatic illustration of a projection exposuremachine according to the invention having a projection lens,

[0029]FIG. 2 shows a section through the lower part of the projectionlens having an end plate and a lens adjacent thereto with a manipulationchamber therebetween, in an enlarged representation,

[0030]FIG. 3 shows a manipulation chamber which is formed by a bipartiteend plate, in an enlarged representation,

[0031]FIG. 4 shows an exemplary embodiment having a manipulation chamberand a further gas interspace, in an enlarged representation,

[0032]FIG. 5 shows a lens section through a first lens arrangement, and

[0033]FIG. 6 shows a lens section through a second lens arrangement.

DETAILED DESCRIPTION OF THE INVENTION

[0034] The principle of the design of a projection exposure machine 1 isdescribed below with the aid of FIG. 1. The projection exposure machine1 has an illuminating device 2 and a projection lens 3. The projectionlens 3 comprises a lens arrangement 4 with a multiplicity of lenses 4 a(not illustrated in more detail in FIG. 1) and an aperture stop 5. Thelenses 4 a are arranged along an optical axis 6. A mask or reticle 7,which is held in the beam path by means of a mask holder 8, is arrangedbetween the illuminating device 2 and the projection lens 3. The mask 7is imaged on an image plane 9 by means of the projection lens 3 by aclearly reduced factor. Such masks 7 used in microlithography have amicrometer or nanometer structure which is imaged on the image plane 13by means of the projection lens 3 in a fashion reduced in size down to afactor of 10, in particular the factor 4. The minimum structures whichcan still be resolved depend on the wavelength (of the light used forthe illumination, and on the aperture of the aperture stop 5, themaximum achievable resolution of the projection exposure machine risingwith decrease in the wavelength of the illuminating device 2 and withincreasing aperture of the projection lens 3.

[0035] A substrate or a wafer 11 positioned by means of a substrateholder 10 is held in the image plane 9.

[0036] The dermination of the projection lens 3 in the direction of thewafer 11 forms a flat end plate 12. A last lens 4 a of the lensarrangement 4 is located at a spacing from the end plate 12. Amanipulation chamber 13, which is sealed off from the surrounding parts,is thereby created between the end plate 12 and the last lens 4 a. Asmay be seen, the side of the last lens 4 a facing the end plate 12 islikewise flat, the result being to surrender the manipulation chamber 13plane-parallel. Of course, it is not mandatory for the side of the lastlens 4 a facing the end plate 12 to be absolutely plane-parallel. Givenappropriately large lens radii, for example with radii R>3000 mm,preferably >5000 mm, plane parallelism is likewise achieved, as it were,and it is thereby possible to influence the production of the sphericalaberration in the manipulation chamber 13 accordingly.

[0037] The manipulation chamber 13 is provided with a pressureconnection 14 via which it can be connected to a gas source (notillustrated in more detail) (see also enlarged illustration in FIG. 2).

[0038] By changing the gas composition, which is introduced into themanipulation chamber 13 starting from the gas source 15, and/or apressure change, changes in refractive index are introduced into theprojection lens 3, specifically shortly ahead of the outlet, and so nofurther imaging errors can be introduced any more. Changing therefractive index creates a spherical aberration which is used tocompensate a spherical aberration occurring in the projection lens 3, orelse to manipulate it in a desired direction.

[0039] Instead of a manipulation chamber between the end plate 12 andthe last lens 4 a adjacent thereto, it is also possible to achieve aplane-parallel manipulation chamber by dividing the end plate 12 intotwo. In this case, the two end plate parts 12 a and 12 b are arranged ata spacing from one another and form the manipulation chamber 13 betweentheir plane-parallel surfaces. Of course, it is necessary in this casefor the two end plate parts to be constructed with an appropriatethickness so that no bending occurs (see FIG. 3). A ratio of thicknessd1 to diameter DU1 of 1:5, preferably 1:3 should be observed for thisreason.

[0040]FIG. 4 shows an embodiment having an additional gas interspace 16as well as the manipulation chamber 13. In order to achieve as high anefficiency as possible for the manipulator, the gas interspace 16 isarranged as near as possible to the wafer 11 such that in this case themanipulation chamber 13 lies correspondingly further to the rear. Thegas interspace 16 is likewise created in this case by splitting the endplate 12 into two into the two plate parts 12 a and 12 b. The interspace16 is likewise connected to a gas source 15′ via a dedicated pressureconnection 14′. By contrast with the manipulation chamber 13, however,at least one of the two surfaces situated transverse to the z directionis provided with a slight curvature 17.

[0041] If it is known that the projection lens is used at a specificbarometric elevation, the following procedure is recommended: Locationof use, for example, at an elevation of 1700 meters with correspondinglyreduced or increased air pressure by comparison with the lensmanufacturer. When the lens is being tuned at the manufacturers, whichis located, for example, at sea level or another lower elevation thanthat of the locations of use, the manipulation chamber is provided witha specifically set gas mixture whose refractive index is higher by therefractive index caused by the pressure difference than that at thelocation of use. In this way, the manipulation chamber can easily befilled later at the location of use with a conventional filling gas, forexample synthetic air, oxygen, nitrogen or helium, at the averagepressure at the installation site, and this results in an exactly tunedlens. Natural weather-induced changes in air pressure are nowcompensated by small pressure changes in the manipulation chamber. Theadvantage of this method consists in that the customer need only fillthe manipulation chamber with conventional filling gas, and only slightpressure differences need be set.

[0042] If it is not desired to stipulate where the later location of useshould be, the conventional filling gas is used for tuning. However, itis then later necessary to use a gas mixture of higher refractive indexat the location of use if the barometric level rises. However, in thiscase pressure changes owing to the weather are likewise compensated bysmall changes in the gas pressure in the manipulation chamber.

[0043] Sections through the lens arrangements are illustrated by theexamples in FIGS. 5 and 6.

[0044] The exemplary embodiments relate to a projection lens 3 having alens arrangement 4 which is subdivided into six optical groups (LG1 toLG6). The first, third and fifth lens groups have a positive refractivepower, and the second and fourth lens groups respectively have anegative refractive power. The subdivision of the lens system into lensgroups is set forth below in more detail, the basis having been providedas the directional propagation of the rays.

[0045] The first lens group LG1 is positive and terminates with a lensof positive refractive power. The first lens cluster forms a bulge, itbeing immaterial whether negative lenses are also arranged in the bulge.

[0046] The second lens group LG2 has an overall refractive power whichis negative. This second lens group LG2 has as first lens a lensconstructed on the image side with a concave lens surface. This secondlens group LG2 essentially describes a waist. It is not important here,either, whether individual positive lenses are contained in the secondlens group LG2, as long as the waist is maintained.

[0047] The third lens group LG3 begins with a lens of positiverefractive power which has on the image side a convex lens surface, andcan be a meniscus. If a thick meniscus lens is provided as first lens,the separation of the lens groups can be conceived inside the lens.

[0048] The fourth lens group LG4 has a negative refractive power. Thisfourth lens group begins with a lens having a negative refractive powerwhich is followed by a plurality of lenses with a negative refractivepower. This lens group forms a waist. It is immaterial whether lenseshaving a positive refractive power are also arranged inside this lensgroup, as long as this influences the optical path only at a shortdistance, and so the waist shape of the fourth lens group is maintained.

[0049] The fifth lens group LG5 has an overall refractive power which ispositive. The first lens of this fifth lens group LG5 has a convex lenssurface on the image side. The fifth lens group LG5 forms a bulge.

[0050] The lens with the maximum diameter (the bulge), is followed by afurther two positive lenses in the fifth lens group LG5, negative lensesalso being permissible. The last lens of the fifth lens group LG5 has aconcave lens surface on the image side.

[0051] The sixth optical group LG6 comprises the optical elementsdownstream of the fifth lens group up to the image plane.

[0052] Such projection lenses are used, in particular, inmicrolithography. They are known, for example, from DE 199 42 281 A, DE198 55 108 A, DE 198 55 157 A and DE 198 55 158 A of the applicant andthe prior art quoted there. These documents are also intended to becontained in this application.

[0053] These lenses in the first and sixth groups conventionally haveair clearances which are delimited by a curved surface up to the airclearance between the object plane and first optical surface, and theair clearance between the last optical surface and image plane, at leaston one side.

[0054]FIGS. 5 and 6 are of similar basic design. In FIG. 5, themanipulation chamber 13 is formed between the end plate 12 and the lens4 a in accordance with the principle illustrated in FIG. 4.

[0055] In FIG. 6, the end plate is of bipartite construction,specifically having the parts 12 a and 12 b, and the manipulationchamber 13 is located therebetween, as may also be seen from theillustration of the principle in FIG. 3. A lens is no longer provided inthe sixth group in the case of this exemplary embodiment.

[0056] A lens 4 c having an aspheric can be provided in the first lensgroup LG1, it being possible for the aspheric to be arranged upstream ofthe first bulge in the light direction. The projection lens 3 preferablyhas a numerical aperture on both sides of at least 0.75, preferably0.85.

[0057] A laser which outputs radiation of wavelength shorter than 250 nmcan be used as light source for microlithography.

[0058] As the case may be, a pattern contained on the mask 11 isappropriately structured after the development of the light-sensitivelayer in the case of the production of microstructure components inwhich the substrate 11 provided with a light-sensitive layer is exposedto ultraviolet laser light by means of the mask 7 and the projectionexposure machine 1.

[0059]FIG. 5 shows the ability to implement a lithographic lens asregards a manipulable plane-parallel air clearance in the outgoing partof the wafer. It has not so far been known to provide such a thickplane-parallel air clearance and a thick plane-parallel plate in a lensopened widely in such a way.

[0060] Aberrations which have so far been corrected in the descendingregion of the third bulge should now predominantly be corrected in theregion of first bulge, first waist, second bulge. It has been found thatthis even exhibits clearly corrective advantages when the optical systemis terminated with a thick plane-parallel plate in the case of thehighest aperture. Consequently, this method was taken further where thethickness of the thick plate is clearly increased. In this case, theratio of thickness to diameter should be at least 1:5. (The two platesact optically like a single thick plate.)

[0061]FIG. 6 shows a design having a particularly thick plane-parallelplate. It constitutes the solution for three further problems at once.

[0062] Very high sine i loadings in the region upstream of the wafer areobtained when correcting highly opened lithographic lenses. Thecurvatures which the individual lenses can now assume, as a sphere, nowcause aberrations with a much different effect between the edge andmiddle of the image field (including above the aperture). These arefrequently effects which are searched for in the lens and which areparticularly provided. Here, in the case of large yields and very highapertures, they can, however, become unmanageable, or certainly at leastdisturb the correction. The solution now actually constitutes a verythick plane-parallel plate which supplies the desired contribution fromspherical overcorrection, but now acts in a completely isoplanaticfashion with reference to the image field. Aperture and image field cannow be made very large.

[0063] In addition to the corrective advantage, it is also possible toreduce the number of lenses by collecting them to form a thickplane-parallel plate. The number of lens surfaces with a very highangular loading such as is usual upstream of the wafer therebydecreases. The advantages are low costs and less reflection losses, andthus a higher transmission. This is important, in particular, forwavelengths of 157 nm and 193 nm. A further aspect is that the thickplate can substantially simplify the number of mounting parts in aregion where there is little space, as is known. Located upstream of thewafer are the most varied image detection sensors which closely adjointhe actual lithographic optical system. The thick plane-parallel platealso creates the possibility here of accommodating more aperture and/ormore field within a specific design space. This is also to be seen inthat it is then possible, for example, to use the same sensor system fora further generation longer.

[0064] A thick plate or thick plates upstream of the wafer are thereforethe solution according to the invention for

[0065] a pressure manipulator upstream of the wafer in the lens,

[0066] improved possibility for correction in conjunction with a veryhigh aperture and large field,

[0067] more aperture and field in conjunction with a given design space,and

[0068] fewer highly loaded surfaces, more transmission.

[0069] In the exemplary embodiment according to FIG. 5, on the firstcurved surface, an aspheric surface takes over tasks which many lensesjust upstream of the wafer have partly also taken over. However, theadvantage here is now the extremely low angular loading on the firstcurved surface. At the same time, because of the good bundle separationit is possible to set a very specific effect with reference to theaction between the middle of the image, the zone of the image field andthe edge of the image field.

[0070] In microlithography, it is also possible in principle to providea plane-parallel manipulation chamber between a last end plate of aprojection lens and a wafer in which the refractive index can be variedby pressure changes and/or changes in gas composition. For this purpose,the interspace between the end plate and the wafer is to be purged withpurging gas of appropriate composition and at an appropriate pressure.It is also required in general for this purpose to

encapsulates

the entire projection lens.

[0071] The design arrangement for the lens arrangements illustrated inFIGS. 5 and 6 are to be specified below in each case by way of example.Of course, the features made concrete with the aid of these exemplaryembodiments and their combinations can be combined with one another.

[0072] Example according to FIG. 5:

[0073] Operating wavelength 1=193.3 nm

[0074] Diameter of the image field=24.6 mm

[0075] Image-side numerical aperture NA=0.85

[0076] Image scale (=−0.25

[0077] Refractive index n(SIO2)=1.5603

[0078] Refractive index n(CAF2)=1.5014 Surface Radius Aspheric ThicknessMaterial Diameter OB 32.000 AIR 1 ∞ 6.329 SIO2 110.8 2 ∞ 1.383 HE 112.53 −1393.131 A 6.329 SIO2 112.8 4 153.737 14.539 HE 118.0 5 191.89023.775 SIO2 135.0 6 −359.189 0.678 HE 136.5 7 −827.276 7.196 SIO2 137.78 −475.714 0.678 HE 138.8 9 296.346 18.036 SIO2 141.7 10 −561.014 0.678HE 141.4 11 183.662 19.090 SIO2 137.2 12 −16545.560 A 0.694 HE 135.1 13326.464 6.329 SIO2 129.2 14 106.348 27.957 HE 118.2 15 −235.452 6.329SIO2 117.5 16 304.109 15.255 HE 118.0 17 −232.751 6.329 SIO2 118.5 18174.842 33.179 HE 127.9 19 −135.497 10.857 SIO2 132.8 20 −567.373 A11.495 HE 160.3 21 −235.399 21.176 SIO2 165.8 22 −145.234 4.213 HE 175.623 −1890.770 49.919 CAF2 219.4 24 −156.092 0.678 HE 224.3 25 340.44566.046 SIO2 255.5 26 −383.246 0.680 HE 254.8 27 137.326 49.212 CAF2218.0 28 457.970 A 0.678 HE 209.9 29 147.683 15.743 SIO2 181.5 30120.693 37.797 HE 159.6 31 −420.368 6.329 SIO2 159.6 32 139.505 25.622HE 140.7 33 −378.597 6.329 SIO2 140.7 34 167.539 39.624 HE 139.8 35−112.503 8.239 SIO2 139.8 36 504.607 18.193 HE 174.3 37 −369.374 15.678SIO2 174.6 38 −205.396 1.373 HE 181.7 39 −1692.687 31.888 CAF2 214.3 40−220.732 1.536 HE 220.3 41 1213.241 32.223 CAF2 256.7 42 −430.691 0.692HE 259.4 43 735.809 63.006 CAF2 274.9 44 −355.045 9.223 HE 278.5 45 ∞0.633 HE 271.7 AS ∞ 0.000 HE 271.7 46 1056.085 20.400 CAF2 272.1 47−5047.421 0.792 HE 271.5 48 260.901 46.828 CAF2 266.8 49 −1697.53423.712 HE 264.5 50 −317.482 10.850 SIO2 264.5 51 −488.982 8.402 HE 262.052 −339.784 13.562 SIO2 262.0 53 −295.518 0.718 HE 261.9 54 152.56537.779 CAF2 213.7 55 505.038 3.020 HE 208.6 56 116.772 28.279 SIO2 168.957 258.363 16.383 HE 160.8 58 −5272.757 A 10.966 SIO2 154.6 59 323.9330.897 HE 133.4 60 142.873 27.124 CAF2 121.2 61 ∞ 8.137 AIR 102.4 62 ∞18.083 CAF2 76.0 63 ∞ 12.000 AIR 51.1 Im

[0079] In the aspherical formula:$z = {\frac{\frac{1}{R}h^{2}}{1 + \sqrt{1 - {\left( {1 - {EX}} \right)\left( \frac{1}{R} \right)^{2}h^{2}}}} + {\sum\limits_{k = 1}\quad {c_{k}h^{{2k} + 2}}}}$

[0080] z is the sagitta; h is the height; R is the radius; EX is theeccentricity; and Ck is the ashperical constant.

[0081] Aspheric at Surface 3

[0082] RADIUS=−1393.13098

[0083] EX=0.0000000000

[0084] C 1=0.4063752600E-07

[0085] C 2=0.2071817000E-11

[0086] C 3=−0.6785322600E-16

[0087] C 4=0.1029460700E-18

[0088] C 5=−0.2998039200E-22

[0089] C 6=0.3527081700E-26

[0090] Aspheric at Surface 12

[0091] RADIUS=−16545.56046

[0092] EX=−43143.0300000000

[0093] C 1=−0.4810999900E-07

[0094] C 2=−0.4047924800E-11

[0095] C 3=−0.8963528600E-16

[0096] C 4=0.8505763100E-20

[0097] C 5=−0.2882210400E-23

[0098] C 6=−0.5453287000E-27

[0099] Aspheric at Surface 20

[0100] RADIUS=−567.37264

[0101] EX=0.0000000000

[0102] C 1=−0.3925583500E-08

[0103] C 2=−0.1562788800E-11

[0104] C 3=−0.1025893700E-16

[0105] C 4=−0.2599978800E-20

[0106] C 5=0.8906747700E-25

[0107] C 6=−0.3796689800E-28

[0108] Aspheric at Surface 28

[0109] RADIUS=457.96974

[0110] EX=0.0000000000

[0111] C 1=0.6773315100E-08

[0112] C 2=−0.3998553500E-12

[0113] C 3=−0.1364056800E-16

[0114] C 4=−0.1474625900E-21

[0115] C 5=−0.2509622300E-25

[0116] C 6=0.1507291900E-29

[0117] Aspheric at Surface 58

[0118] RADIUS=−5272.75688

[0119] EX=0.0000000000

[0120] C 1=−0.1963426400E-07

[0121] C 2=0.2768505300E-12

[0122] C 3=0.1262120200E-15

[0123] C 4=−0.1811119000E-19

[0124] C 5=0.1171493900E-23

[0125] C 6=−0.3104888900E-28

[0126] Example according to FIG. 6:

[0127] Operating wavelength 1=248.4 nm

[0128] Diameter of the image field=27.2 mm

[0129] Image-side numerical aperture NA=0.8

[0130] Image scale β=−0.25

[0131] n(SIO2)=−1.5084 Surface Radius Aspheric Thickness MaterialDiameter OB ∞ 32.000 AIR 1 ∞ 4.253 AIR 121,9 2 −1143.702 7.789 SIO2122,9 3 366.821 11.482 AIR 127,5 4 249.157 23.794 SIO2 138,2 5 −289.4240.750 AIR 139,4 6 329.633 18.667 SIO2 140,7 7 −444.218 0.750 AIR 140,2 8268.864 16.633 SIO2 135,5 9 1167.441 A 0.750 AIR 131,9 10 360.081 8.628SIO2 129,2 11 118.445 21.270 AIR 120,1 12 −775.270 7.000 SIO2 119,7 13156.713 23.965 AIR 118,8 14 −190.304 7.000 SIO2 119,8 15 266.520 27.800AIR 131,4 16 −141.408 7.149 SIO2 134,4 17 2327.162 A 7.878 AIR 162,8 18−999.626 32.538 SIO2 169,4 19 −148.399 0.750 AIR 177,5 20 −1179.797 A40.792 SIO2 207,1 21 −190.467 0.750 AIR 215,0 22 506.448 42.194 SIO2236,0 23 −318.978 0.750 AIR 236,6 24 156.565 61.867 SIO2 220,3 25−1909.591 A 0.750 AIR 209,4 26 305.588 22.962 SIO2 186,3 27 178.41227.808 AIR 157,7 28 −441.206 7.000 SIO2 154,8 29 141.453 34.534 AIR138,2 30 −176.778 7.000 SIO2 137,5 31 204.086 40.524 AIR 141,8 32−114.660 7.000 SIO2 143,5 33 1254.417 16.848 AIR 176,1 34 −386.52031.318 SIO2 181,6 35 −187.128 0.750 AIR 198,8 36 −7551.297 32.372 SIO2235,1 37 −271.610 0.750 AIR 239,3 38 985.139 48.181 SIO2 264,8 39−280.307 0.750 AIR 266,7 40 485.845 42.861 SIO2 265,0 41 −19641.1720.750 AIR 260,0 42 ∞ 0.750 AIR 259,6 AS ∞ 0.000 AIR 259,6 43 413.81231.899 SIO2 258,5 44 −1463.530 41.090 AIR 257,1 45 −229.000 7.000 SIO2252,9 46 −761.338 16.518 AIR 258,2 47 −346.924 22.741 SIO2 258,3 48−221.418 0.750 AIR 260.0 49 265.978 21.446 SIO2 240.4 50 700.398 0.750AIR 238.8 51 203.760 28.367 SIO2 224.4 52 565.063 0.750 AIR 219.8 53124.657 33.574 SIO2 185.9 54 255.790 3.089 AIR 175.4 55 192.512 17.352SIO2 164.2 56 490.117 A 9.135 AIR 155.9 57 ∞ 57.580 SIO2 148.9 58 ∞2.600 AIR 76.6 59 ∞ 8.069 SIO2 69.6 60 ∞ 12.000 AIR 59.5 IM

[0132] In the aspheric formula:$z = {\frac{\frac{1}{R}h^{2}}{1 + \sqrt{1 - {\left( {1 - {EX}} \right)\left( \frac{1}{R} \right)^{2}h^{2}}}} + {\sum\limits_{k = 1}\quad {c_{k}h^{{2k} + 2}}}}$

[0133] _z is the sagitta; h is the height; R is the radius; EX is theeccentricity; and Ck is the ashperical constant.

[0134] Aspheric at Surface 9

[0135] RADIUS=1167.44078

[0136] EX=−148.8088700000

[0137] C 1=−0.3810274500E-07

[0138] C 2=0.1825110100E-11

[0139] C 3=0.8703118800E-16

[0140] C 4=−0.2547944400E-19

[0141] C 5=0.2618280200E-23

[0142] C 6=−0.7405173000E-28

[0143] Aspheric at Surface 17

[0144] RADIUS=2327.16189

[0145] EX=−543.6641800000

[0146] C 1=0.1496899300E-07

[0147] C 2=0.4053465300E-11

[0148] C 3=−0.3692162500E-16

[0149] C 4=0.1322169800E-19

[0150] C 5=0.7575130800E-24

[0151] C 6=−0.1121083700E-27

[0152] Aspheric at Surface 20

[0153] RADIUS=−1179.79732

[0154] EX =88.7124390000

[0155] C 1=−0.5780601700E-08

[0156] C 2=0.2633543200E-12

[0157] C 3=−0.3666325900E-16

[0158] C 4=0.793956500E-21

[0159] C 5=−0.7002646400E-26

[0160] C 6=−0.4010891200E-29

[0161] Aspheric at Surface 25

[0162] RADIUS=−1909.59064

[0163] EX=0.0000000000

[0164] C 1=0.5895489200E-08

[0165] C 2=0.4254414900E-13

[0166] C 3=−0.4954342300E-18

[0167] C 4=−0.9017812800E-21

[0168] C 5=0.3307499000E-25

[0169] C 6=−0.5028285900E-30

[0170] Aspheric at Surface 56

[0171] RADIUS=490.11681

[0172] EX=−4.7440051000

[0173] C 1=0.6613898200E-08

[0174] C 2=−0.9371994200E-12

[0175] C 3=0.7675398100E-16

[0176] C 4=−0.9919946900E-20

[0177] C 5=0.9420632400E-24

[0178] C 6=−0.4092113200E-28

1. Projection lens, having an object plane, having an image plane,having a lens arrangement and having at least one gas chamber filledwith gas or through which gas flows, wherein the gas chamber isconstructed as an at least approximately plane-parallel manipulationchamber, and wherein the manipulation chamber in connected with pressurechange means.
 2. Projection lens, having an object plane, having animage plane, having a lens arrangement and having at least one gaschamber filled with gas or through which gas flows, wherein that the gaschamber is constructed as an at least approximately plane-parallelmanipulation chamber, and wherein the manipulation chamber in connectedwith gas composition change means.
 3. Projection lens, having an objectplane, having an image plane, having a lens arrangement and having atleast one gas chamber filled with gas or through which gas flows,wherein that the gas chamber is constructed as an at least approximatelyplane-parallel manipulation chamber, and wherein the manipulationchamber in connected with pressure change means and gas compositionchange means.
 4. Projection lens according to claim 1, 2 or 3, whereinthe manipulation chamber is located between the lens arrangement and theimage plane.
 5. Projection lens according to claim 1, 2 or 3, whereinthe manipulation chamber is located in the lens arrangement. 6.Projection lens according to claim 5, wherein the manipulation chamberis arranged between an end plate and the lens situated adjacent to theend plate.
 7. Projection lens according to claim 5, wherein an end plateof the lens arrangement is bipartite, and wherein the two end plateparts are arranged at a spacing from one another and form themanipulation chamber between them.
 8. Projection lens, having a lensarrangement comprising a first lens group (LG1) of positive refractivepower, a second lens group (LG2) of negative refractive power, a thirdlens group (LG3) of positive refractive power, a fourth lens group (LG4)of negative refractive power, a fifth lens group (LG5) of positiverefractive power, and a sixth optical group (LG6), wherein there isprovided in the sixth optical group a first optical element with radiiof curvature R1 and R2, a thickness d1 and a diameter DU1, wherein itholds that |R1|>3000 mm, |R2|>3000 mm and$\frac{d1}{DU1} > {\frac{1}{5}.}$


9. Projection lens according to claim 8, wherein it holds that |R1|>5000mm and |R2|>5000 mm.
 10. Projection lens according to claim 8, whereinit holds that$\frac{d1}{DU1} > {\frac{1}{4}\quad {preferably}\quad \frac{d1}{DU1}} > {\frac{1}{3}.}$


11. Projection lens according to claim 8, 9 or 10, wherein the firstoptical element and a second optical element of the sixth optical groupenclose a gas chamber, wherein it holds for the radius of curvature R3of the surface of the second optical element, which faces the firstlens, that: |R3|>3000 mm.
 12. Projection lens according to claim 11,wherein it holds for the radius of curvature R3 that: |R3|>5000 mm. 13.Projection lens according to claim 11 or 12, wherein it holds for theradius of curvature R4 of the further surface of the second opticalelement that: |R4|>3000 mm, preferably |R4|>5000 mm.
 14. Projection lensaccording to claim 11, wherein the second optical element has athickness d2, wherein it holds that: d1+d2>60.0 mm.
 15. Projection lensaccording to one of the claims 1 to 14, wherein a lens with an asphericsurface is provided in the first lens cluster (LG1).
 16. Projection lensaccording to claim 15, wherein the lens with the aspheric surface isarranged upstream of the first bulge in the light direction. 17.Projection lens according to claim 15 or 16, wherein the asphericsurface is arranged on the first curved surface of the aspheric lens.18. Projection lens according to at least claim 1, wherein theprojection lens has on the image side a numerical aperture of at least0.75, preferably 0.85.
 19. System for projection lens, having an objectplane, having an image plane, having a lens arrangement and having atleast one gas chamber filled with gas or through which gas flows,wherein the gas chamber is constructed as an at least approximatelyplane-parallel manipulation chamber, and wherein the refractive indexcan be varied in the manipulation chamber by pressure changes. 20.System for projection lens, in particular for microlithography, havingan object plane, having an image plane, having a lens arrangement andhaving at least one gas chamber filled with gas or through which gasflows, wherein the gas chamber is constructed as an at leastapproximately plane-parallel manipulation chamber, and wherein therefractive index can be varied in the manipulation chamber by changes ingas composition.
 21. System for projection lens, in particular formicrolithography, having an object plane, having an image plane, havinga lens arrangement and having at least one gas chamber filled with gasor through which gas flows, wherein the gas chamber is constructed as anat least approximately plane-parallel manipulation chamber, and whereinthe refractive index can be varied in the manipulation chamber bypressure changes and changes in gas composition.
 22. System forprojection lens according to claim 19, wherein the offset of therefractive index can be set via the gas composition in such a way thatthe refractive index can be manipulated in both directions.
 23. Systemfor projection lens according to claim 20, wherein the offset of therefractive index can be set via the gas composition in such a way thatthe refractive index can be manipulated in both directions.
 24. Systemfor projection lens according to claim 21, wherein the offset of therefractive index can be set via the gas composition in such a way thatthe refractive index can be manipulated in both directions.
 25. Systemfor projection lens according to claim 19, wherein in addition to themanipulation chamber a further at least approximately plane-parallelmanipulable gas interspace is provided, for the purpose of removingfield curvature, on a substrate, which is to be exposed, in the sixthoptical group (LG6).
 26. System for projection lens according to claim20, wherein in addition to the manipulation chamber a further at leastapproximately plane-parallel manipulable gas interspace is provided, forthe purpose of removing field curvature, on a substrate, which is to beexposed, in the sixth optical group (LG6).
 27. System for projectionlens according to claim 21, wherein in addition to the manipulationchamber a further at least approximately plane-parallel manipulable gasinterspace is provided, for the purpose of removing field curvature, ona substrate, which is to be exposed, in the sixth optical group (LG6).28. Projection exposure machine in microlithography, having a lightsource which outputs radiation of wavelengths shorter than 370 nm, whereit comprises a projection lens according to at least one of thepreceding claims.
 29. Method for producing microstructured components,in the case of which a substrate provided with a light-sensitive layeris exposed to UV light by means of a mask and a projection exposuremachine with a lens arrangement, wherein an at least approximatelyplane-parallel manipulation chamber which is connected to a gas sourceis created in the projection exposure machine, the refractive indexbeing manipulated by pressure changes and/or changes in gas composition.30. Method according to claim 29, wherein the manipulation chamber isinstalled in the projection lens on the input side of the lensarrangement or on the side of the mask.
 31. Method according to claim29, wherein the manipulation chamber is installed on the output side ofthe lens arrangement or on the side of the wafer.
 32. Method accordingto claim 29, wherein the manipulation chamber is installed between thelens arrangement and the image plane.
 33. Method according to claim 29,wherein the plane-parallel manipulation chamber is sealed off from thesurroundings, and in that a gas mixture is led to the manipulationchamber in a controlled fashion via a pressure connection.
 34. Methodaccording to claims 29 and 33, wherein when the projection lens is beingtuned a filling gas is introduced which is subsequently exchanged by theoperator for a gas mixture.
 35. Method according to claim 27, whereinprovided in addition to the manipulation chamber is a furthermanipulable gas interspace, by means of which a field curvature on thesubstrate to be exposed can be removed.
 36. Method for producingmicrostructured components, in the case of which a substrate providedwith a light-sensitive layer is exposed by ultraviolet light by means ofa mask and a projection exposure machine according to claim 26 and, ifappropriate, is structured after the development of the light-sensitivelayer in accordance with a pattern included on the mask.
 37. Projectionlens for the microlithography, having an object plane, having an imageplane, having a lens arrangement and having at least one gas chamberfilled with gas or through which gas flows, wherein the gas chamber isconstructed as an at least approximately plane-parallel manipulationchamber, and wherein the manipulation chamber in connected with pressurechange means.
 38. Projection lens for the microlithography, having anobject plane, having an image plane, having a lens arrangement andhaving at least one gas chamber filled with gas or through which gasflows, wherein the gas chamber is constructed as an at leastapproximately plane-parallel manipulation chamber, and wherein themanipulation chamber is connected with gas composition change means. 39.Projection lens for the microlithography, having an object plane, havingan image plane, having a lens arrangement and having at least one gaschamber filled with gas or through which gas flows, wherein the gaschamber is constructed as an at least approximately plane-parallelmanipulation chamber, and wherein the manipulation chamber is connectedwith pressure change means and gas composition change means.